Thermostatic governor for gas ovens



--April zo, 1926.

" H. W. PARTLOW THERMOSTATIC GOAVERNOR FOR GAS OVENS- Filed Sept. 20, 1922 '2 Sheets-Shedl l bbomw/id/ April 20', 1926. I 1,581,139

H.w. PARTLow THERMOSTATIC GOVERNOR FOR GAS OVENS Filed Sept. 20, 1922 2 Sheets-Shea?, 2

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Patented Apr. 20, 1926.

`PATENT OFFICE. y

HOWARD WEBSTER PARTLOW, 0F UTICA, NEW YORK.

THEBMOSTATIC GOVERNOR FOR GAS OVENS.

Application tiled September 20, 1922. Serial No. 589,375. i

To all 'whom it may concern.'

Be it known that I, HOWARD WEBSTER PAR'rLow, a citizen of the United States, residing at Utica, in the county of Oneida and State of New York, have invented certain new and useful Improvements in Thermostatic. Governors for Gas Ovens, of which the following is a specilication.

This invention relates to improvements in tlierniostatic governors for gas-heated appliances, and has for its object to provide a fuel governing` mechanism, which may be applied to any gas heater, for automatically maintaining any desired predetermined te1nperature, whereby cooking, baking, as well as other foriiis of heating may beeconomb cally and accurately effected. And a particular object is to provide a thermostatic governor for gas-ovens and the like, which.

is novel, simple andinexpensive, and whichy effectually prevents excessive heating, as`

well as waste of the fuel. y

. I attain these objects by the means set forth in the detailed description which fob lows, and as illustrated by the accompanying drawings, in whicli- Figure 1 is a front elevation ofan ordiiiarykkitchen gas-range with the oven doors removed, to which my governor is applied: Fig. 2 is an end elevation of the range. Fig. 3 is an enlarged side velevation of the governor. Fig. t is a central vertical section, taken on line 4-4 of Fig. 5; 4showing the construction,- arrangement and operation of the governiint;- parts. Fig. 5 is a rearface view of the body with the cover removed. Fig. 6 is a. top-plan view of the body. Figi 7 is a detached view of the link mechanism through which the thermostatie element operates the gras valve. And Fig. 8 is a rear-edge view of the same.

In the drawings, 2 represents an ordinary gas-range, and 2 is the oven. 3 represents.

the usual tubular burners, which extend transversely through the lower portion of the oven 2", the corresponding ends of the burners being` fitted with the usual funnelshapcd mixers 3', which ordinarily receive the {iuid or gaseous fuel from a common manifold 1i, by means of separate pipes 4. The `as is supplied to the manifold by a pipe 4*, which is preferably divided interiorly by a plug 4b. and at the opposite sides of the said plug the said pipe is tapped by 'relatively low expansibility.

similar; nipples @-4151, which conduct the gas towards and from the thermostatic gov,- ernor, which will now be described.

5 represents the hollow body of the gov'- i ernor, which has one open side thatf is normally closed and sealed gas-tight by a cover .5 and a packing 5, Awhich are held in place by screws 5*. Depending' from the bottom of the body is a reduced portion 5, which is provided with a gas-receiving opening' 5d, the latter connecting with the nipple 4c by a pipe 4e. The part 5c is also provided with a similar threaded gas-outlet opening'", the gas being conducted from the latter opening towards the nipple 4d, by a pipe 4f. Within the body 5 is-disposed a tubular valve casing G, whose lower end G is threaded into the passage 5G, the interior of said casing being v formed with an annular seat 6 for a spherical valve 7, which controls the delivery of the fuel to the oven burners 3. The plug 4b is employed for diverting the fuel gas from one portion of the pipe 4 towards the body other, except attheir opposite ends where they are preferably only frictionally connected as shown. One 3nd of the tube 8 is threaded for screwing into a threaded opening 5r of the body, which positions the meinber 8 at right angles to the longitudinal axis of the body 5. The "outer or free end of the ltube 8 is preferably closed and interiorly is formed with a socket 8, which receives the outer end of the rod 8u and holds the said rod substantially concentrically in the tube. Adjacent the body 5 the rod 8a is provided with an annular shoulder 8C, which operatively iits the bore of the tube, and its inner end is formed into a linger 8, which normally projects beyond the corresponding end of the tube 8 and is in constant operative engagement with the governing mechanism supported when unseated by a rod 7 whose upper end is secured to a lug 10 of a bar 10, the upper end of said bar being pivoted to one end cfa link 11 by a pin 11. The link 11 is pivoted near its middle by a pin 11a to a sleeve 12, the latter having its lower end slotted at 12" to receive the link 11. The

opposite end of the link 11 is pivoted to a similar vertically disposed link 13 by a pin 13', the lower end of the link 13 being piv- `oted to the long arm of a bell-crank lever 14a'of the bell-crank, which extends above the pivot 14 is'disposed opposite the opening 5t of the body and directly in the path of the finger 8d, the said parts being held constantly engaged by a spring 14. A second spring 14l has one end thereof secured to the link 11 through the medium of a pin 14, the other end of said spring being secured to the top .of the body 5 by any suitable means such as a screw 14f, for equalizing and holding the movable parts in adjusted position.' By this construction and arrangement of the parts, the lengthening and shortening of the rod 8a by the changing temperature 'of the oven 2, correspondingly rocks the bell-crank 14 on its pivot 14 for raising and lowerincr the valve 7 (see full and dotted lines in *ign 7 which may be accomplished by the link 11 being rocked vertically on the pivot 11,

The sleeve 12 is supported by a vertically disposed screw 16, which is adjustably supported by a bushing 17, the latter being threaded into the top-end of the casing 5, as shown in Fig. 4. lThe sleeve 12 being held from rotation by the link 11 moves Verticali y on the worm 16. The worm 1G extends through the bushing 17 and supports a cylindrical dia-l 18, the latter having a hub 18 which supports a set-screw 18, by which the -dial is made rigid to the worm. To the top end of the screw 16 is fitted a handknob 19, by which the screw may be rotated for raising and lowerin the sleeve 12 and for correspondingly raising and lowering the link 11 and the valve 7, as shown by the full and dotted lines in Fig. 4, for predetermining the temperature of the oven 2', for baking, cooking and the like. The dial 18 is graduated and numbered, as best seen in Figs. 3 and 5, and the various adjustments are conveniently indicated by a pointer 20, which is supported by the top end of the body 5. In Fig. 3 the dial is shown Set for indicating an oven temperature, of 400, which for example is the temperature required for baking bread, and certain other articles, as shown by a table or schedule 21, which is inscribed 0n the front face of the body 5 (see Figs. 1 and 3). The table 2l forms an important feature of the thermostatic governor when taken in connection with the dial 18, and the governor cannot be intelligently operated without these two important elements. Every different article placed in the oven 2', as a rule, requires a certain temperature and time 'for baking or.

cooking the said article.v The table 21 has been compiled after consulting the highest authorities on food preparation and heating generally, so that when the present governor is adjusted and set according to the dial for a given temperature, like 400, as shown, the said adjustment is made in accordance with the table 21, and the result of the cooking operation. will be exactly what the predetermined or indicated temperature will produce. The worm 16 being supported entirely by the bushing 17, its rotation in 0pposite directions correspondingij.7 raises and lowers the sleeve 12, as shown bj; the dotted line-s in Fig. 4. After the goverimr has been H be in the positions shown by the full lines in Fig. 7. The several parts will remain in the last named position as long as the temperature of the oven registers 400. But as soon as the temperature of the oven vrises above 400, the expansion or lengthening of 105 the tube 8 frees the rod 8 suiliciently to effect the relaxing of the tension or pressure of the linger 8d against the tip 14a of the bell-crank. This effects the leftward movement of the said tip and the corresponding upward swing of the longer arm of the bellcrank 14, which is constantly under the tension of the spring 14C. The upswing of the bell-crank through the link 13 correspondingly rocks the link 11 in the direction-for 115 lowering the valve 7 towards its seat in the casing (Ll-thereby reducing the flow of the gas towards the burners 3. The reduction of the gas instantly effects the lowering of the temperature to the predetermined degree,

viz., 4000, for example, `in accordance with the adjustment of the dial. 18, as described. In case the temperature of the oven falls below 400, the cooling of the oven effects the contraction of the tube 8', which forces therod 8Il endwise towards the lever 14 and causes the tilting of said lever and related parts in the proper direction for lifting the valve 7 away from itsl seat for increasing the supply of gas to the burners 3. The .130'

threads of the screw 16, in the present device to the neutral line shown in Fig.- 5. A

small pipe 24'connects with the supply pipe 4a beyond the plug 4b, and then extends into the oven alongside of the burners 3, for providing one or more pilot lights 24', for ignitiiig the burners whenever the oven is to be operated. l v

Owing to the size of the oven Q', it is.

necessary topro'vide a relatively long ther? mostatic member 8, in order to properly regulate the temperature of the oven.

For the outer thermostatic member, as 8', I employ a metal of great expansibility, which preferably' 'has fa. very high yfusing point, while lthe inner thermostatic member,

Vas 8", preferably comprises metal having the lowest expansion. Practice however, has proven that the relatively long tube 8 has too great linear variation to admit of fine and close adjustment of the fuel regulating parts. In order to overcome this trouble, the rod 8 is preferably-made in two parts, c and d, as shown-in Fig. 3, wherein the part .c preferably comprises a short section of common Bessemer steel, while the longer part is preferably made of invar steel.- In the present device, the part c is relied upon for effecting practically the entire linear ex-` pansion and contraction of the secondary thermostatic element 8, it being well-known that invar steel has scarcely any expansibility. By this construction and arrangement; the linear variations of the element 8a are so very slight that so small a change in the temperature of the oven as one-half degree -orv even less, will result in increasing and decreasing the iiow of the gas to the burners 3, for maintaining the temperature of the oven at any predetermined stage.

. Having thus described my inventiomwhat I claim, is y 1. In combination with a burner and a valve for controlling the supply of fuel thereto, a thermostat arranged to be acted on by the heat from the burner .and includ- `ing a movable element, a rocka'ble lever hav ingl a fixed fulcruin and one end 'disposed to be engaged and actuated by said movable element, a second lever, an adjustable fulcruin mounting the second lever between its ends for positive adjustment, a link connecting the other end of the first lever to one end of the second lever, and a second link connectinof the oppositeend of thesecond lever to the valve for controlling the same.

2. In combination with a burner and a valve for controlling the supply of fuel thereto, a hollow bodyinclosing the valve, a thermostat mounted on the body and extending therefrom into the heat zone of the burner, said thermostat including a movable element projecting into the hozllow body, afulcrum block within, the hollow body adjacent the projecting end of said movable element, a lever pivoted between its ends to the block with one end overlying the pro# jecting end aforesaid, spring means normally urging said overlying end against said projecting end of the element, a second lever, a fulcrum support mounted for adjustment and pivoting said second lever between its ends, a link connecting the opposite end of the first lever to one end of the second lever, and means connecting the opposite end of the'second lever to the valve.

3. In a thermostatic governor for gas ovens, a hollow body, a thermostat extendinfr laterally therefrom and including a mov abIe element projecting into the hollow body, a fuel valve in one end of the hollow body for controlling the supply `of fuel to the burner of the gas oven,afulcrumsupport adjustably mounted in the opposite end of the hollow body for adjustment toward and from the valve, a lever pivoted between its ends to the support, means connecting one end of the lever to the valve, a second lever having a xed pivot in the hollow -body and arranged to be actuated by the movable element, and means connecting the opposite end of thefirst lever to the second lever for operation thereby.

4. A thermostatic governor for gas jovens according to claim 3, characterized by the 4fulcrum support comprising a worm shaft ing the second lever into contactwith the A movable element. Y r.

5. A thermostatic governor for gas ovens according to claim 3, characterized by the fulcrum support comprising a worm shaft journaledin said opposite end of thehollow body, a split sleeve providing a fulcrum Support carried by the worm shaft for vertical .adjustment therewith and pivotally conto equalize and hold the movable parts in adjusted position.

In testimony whereof I affix ,my vsig'naf ture. i l

HOWARD WEBSTER PARTLOW. 

